One of the biggest difficulties
that the early explorers faced when looking for the Northwest
Passage was the inconsistency of the pack ice along any likely
route.

One year for instance a ship
would report that it sailed a particular route easily for
hundreds of miles without much difficulty before getting stuck
someplace and unable to proceed any further. Communications
being almost non-existent meant that the next expedition would take
place the next year or later. So having reported back, others
would set off on the same route to find that year after only a
few tens of miles they encountered consolidated pack ice as far
as the eye can see. They would then set off on another potential
route which may end up equally blocked or turn out to be
fruitless as a route through the Arctic.

This is ice that is in Lancaster
Sound though no problem to shipping as there was plenty of open
water as well.

Air temp: +5º C Latitude: 74º 34' N Longitude: 88º 58' W

These are pictures
from a cruise to the High Arctic in August 2010, from Resolute
Bay Canada to Kangerlussuaq in Greenland.
Pictures copyright Paul Ward.
Pentax digital equipment.